How important is the MIPS safety system for a bicycle helmet? [duplicate]

Question

I'm shopping for a bicycle helmet. The ones without this "MIPS" feature can cost 549 SEK: https://www.sportson.se/produkt/miles-69415850

But then there is an identical-looking one with "MIPS" which costs 799 SEK: https://www.sportson.se/produkt/miles-mips-69415902

MIPS = "MIPS-C2® Brain Protection System".

It seems to be a big deal, but if so, why do they still sell helmets without that feature? It seems like some sort of "premium" security feature. Still, if I'm finally buying one of these things, after jeopardizing my life for so many years since I was a little kid and started thinking that helmets look lame, I might as well buy a proper one... within reason. The really good ones seem to cost over 1,000 SEK, but I'm not spending that kind of money... Even 500-800 SEK feels more than costly enough, even with today's hyper-inflation in the prices of everything.

Has anyone even heard of "MIPS" outside of Sweden? Is it a big deal? Is it worth paying extra for it?

Answer 1

All bicycle helmets are subject to the same standardized set of impact tests during the certification process. If the helmet product passes, it meets the minimum criteria for protection, regardless of how much it costs, weights and which proprietary technologies it uses.

The subtle point here is that the existing certification protocols are rather conservative in what sorts of impacts and damages they attempt to simulate. Certain helmet manufacturers went farther to cover additional classes of harmful events, such as rotational forces. But there are yet no standards to cover those, so you'll have to do your own research and ultimately believe (or not) in what the specific vendor claims about their product on top of the "standard" level of protection.

There are several competing technologies in the area, including MIPS, WaveCel and SPIN. MIPS was the first one to the worldwide market and is most known.

If you are interested in details, it is worth reading https://helmets.org/mips.htm (warning: long read) by Bicycle Helmet Safety Institute, an independent helmet safety research group. If you want more data by research groups, see papers listed here: https://helmets.org/journals.htm#helmets

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As for the price. If used for commuting and no crashing, a helmet might serve you 5 years daily before it has to be replaced (mostly because of worn straps and padding, not actual damage to the foam). At the price of 550 kr, that'd be 30 öre per day. At the price point of 800 kr, it would be 43 öre/day.

Finally, a personal view on the topic. I recently crashed hard (face-planted) on a black DH track. I smashed my full-face helmet to the point when I consider it to be unsafe to use in the future. But it literally saved my skull from a rock and my brain from any damage. I will gladly pay twice/thrice the amount you are considering for this level of safety.

As for the looks, most people in Sweden use helmets regardless of age when cycling, even though it is not required by the law (for adults). You wearing a helmet won't stand out, rather the opposite.

Answer 2

MIPS has become common in at least mid-to-high end mountain biking helmets in the US over the last decade. The https://mipsprotection.com/ web site has some descriptions, but my general understanding is that MIPS systems have an inner shell next to the head that can rotate somewhat relative to the main helmet shell. This serves to reduce the peak (sideways) acceleration forces generated by many sideways impacts to the helmet. An example might be a tree limb sideswiping the helmet, or something catching on the visor area and snapping the top of the helmet backward.

Answer 3

This study is the most scientific resource I was able to find. It compares several rotation damping systems to a standard helmet without any additional safety measures.

I made a quick overview with the most relevant data and figures. CONTROL is the standard helmet, and MIPS is the exact same model equipped with Mips. (ODS, LDL and SPIN are other safety systems that are not relevant for this question.)

While the peak rotational acceleration gets only decreased by about 20%, it seems the probability of an AIS 2 brain injury gets almost cut in half. I'm not sure how exactly this probability is calculated, but in any case the difference at least seems to be in a relevant range.

It should however be noted that these numbers applies to the test case only, and it is hard to say how often a similar scenario occurs in the real world. As Mips themselves say in their FAQ about how much protection the system actually adds:

That depends on the individual helmet, the person and the accident. Every crash is unique and every person is unique. So, you can never state any claims on how a certain helmet will add protection.

Answer 4

MIPS is a safety improvement, but it's not the next level of protection, like a motorcycle helmet would be. It's a more flexible mounting system, which can sometimes reduce injury. Basic helmets are being sold because they're still very effective, vs nothing at all.

The step that matters most is any helmet vs. no helmet.

Past that, the differences are small. Some MTB helmets extend further over the back of your head. Some road helmets offer better cooling or aerodynamics.

The most important thing in a helmet is good fit, so that you actually wear it while riding. Among helmets that fit, paying for safety features is worthwhile. Don't expect wonders, all helmets are made from EPS foam.

MIPS does have some drawbacks. The whole point is that the helmet is allowed to rotate more around your head, making it worse for fitting accessories.

If you're not comfortable with how a helmet fits, look for others. Between two helmets that both fit well, MIPS (or SPIN) is an improvement. At the end of the day, any helmet is only limited protection that reduces, not eliminates, the risk of injury in moderate impacts.

Answer 5

You are asking "How important is it?", so let me compare it to other things that are important:

With bicycle helmets, you have a 3-dimensional decision problem. All helmets have three major properties or attributes in which they differ:

1. Exists (yes/no)
2. Full-face (yes/no)
3. MIPS (yes/no)

These three are very different in impact. Obviously the first question is whether you have a helmet at all - the highest impact. It improves your chances against brain damage, and sharp/blunt trauma against skin/bone of the top and back of your head.

The second most important difference is surely whether it offers full-face protection. Half-helmets do not protect against face-plants, or maybe worse, sliding over concrete with your face down, and landing towards the front is not exactly an uncommon experience (the classic "over the handlebar" maneuver). Sharp, blunt or sliding impacts to the face can be literal life changers. Think about living without an eye, with a badly deformed nose, a few less teeth, or with a large chunk of skin ripped off your cheek. Regardless of likelihood, the impact on your future can be very uncomfortable (self-healing abrasions), to very costly (requiring plastic surgery in a country where this is not covered by a health service) to most severe (life-threatening in the case of punctured eyes/ears).

The third, MIPS, protects against one single problem: in a nutshell, a helmet makes the circumference larger compared to your head, and through its design (with the air holes etc.) also makes it easier to snag on something while sliding over ground - in total, the risk is that your head/neck being turned with a higher torque. How significant this problem is is hard to tell, I don't know of independent, large-scale statistics. The study brought up by @ZOMVID-20 is very detailed, but if you check the very last paragraph in their conclusion, they point out that more work needs to be done, and that it is a relatively small portion of the torque that is negated. So it's more of a gradual improvement than being a life-saver like the first two.

So the importance is clear to me:

1. Wear a helmet
2. If you can, use a full-face version
3. If you can, add MIPS as well

Answer 6

MIPS allows the helmet to rotate somewhat around your head, so there is no rotational forces if you receive a glancing blow. That is, when you fall at speed and hit the side of your helmet, that will generate a spinning moment on your head, which can be dangerous for your brain. MIPS reduces this by allowing the helmet to rotate slightly. Or so the theory goes.

To be honest, I'm not convinced. When you fall you don't just flop down like a rag doll, your reflexes try to reduce damage. I find it hard to imagine a scenario where you hit the ground without your neck muscles overcoming any rotational moment. That's why helmets have shells - to make them more slippery and protect your head and neck from strain. I have been involved in a crash in a peloton (I rode over another bloke who fell earlier), I fell directly on my side and cracked a rib, but my helmet hasn't even touched the ground, my reflexes held the head away from the road.

So yeah, I'm sure this shows good results in a lab with sensor-heads not physically connected to anything which measure rotational moments but I don't think it does anything much in the real world. You'd need a contrived scenario where you hit the ground already unconscious and unable to react. I don't think it's worth it, unless it's built in at no extra cost.

I'd say go for the cheaper non-MIPS one. The big safety gain is wearing A helmet, no matter which name brand and what safety features and how pricey. The gain above that from MIPS is minuscule, if not entirely theoretical.

Answer 7

In general, when talking about bicycle helmets we should remember that in countries with nearly 0% helmet adoption rate, after enforced helmets laws were enacted, causing nearly 100% helmet adoption rate, we usually see only very slight reduction in cyclist fatalities. Usually that reduction is similar to the reduction of cycling in general (every mandatory helmet law causes a reduction in cycling, if enforced). So based on this it appears that bicycle helmets do not seem to be particularly effective.

The studies that show otherwise (claiming that helmets are X% efficient with a large value of X) usually have a very wide definition of "head injury". For example, if your worst fear is that you could have a bleeding wound in your head, a helmet is approximately 100% efficient against that. But most people want something more from a helmet -- not just protection against minor injuries, but protection against major injuries and death.

The cause for this wide definition of "head injury" is that cycling is an extraordinarily safe activity, and so getting enough cases of "head injury" that are actually severe injuries would require a whole population and not just a subset. A scientist cannot reasonably collect enough data from other sources than nationwide statistics, so they expand the definition of "head injury" used in studies (and thus come to a false conclusion).

We also know that since a typical helmet does not have MIPS, that helmets are not actively harmful. One of the theories behind MIPS is that a helmet could cause rotation of the skull, causing a brain injury, and therefore riding with a helmet would be more harmful than riding without a helmet. This theory is false, because otherwise the countries with suddenly enacted enforced helmet laws would see a rapid increase in severe head injuries.

Yet the MIPS theory might have some merit: for example if a helmet with MIPS causes 50% reduction in severe injuries and deaths, it could be possible that missing MIPS would increase injuries by 50%, so a non-MIPS helmet could cause approximately 0% reduction in severe injuries and deaths (which we have observed in countries with sudden helmet wearing spike due to enforced helmet laws). So I can't conclusively prove that MIPS would be unnecessary. Getting enough data would require a country with 0% helmet adoption rate and lawmakers willing to enact legislation that would make riding illegal without a MIPS helmet, and actively enforcing that legislation (so every cop seeing a helmeted cyclist would need a way to quickly tell if it's a MIPS helmet).

If shopping for a helmet, I would consider this list a bare minimum:

• Better protection than the minimum helmet requirements. In Europe, the minimum is EN 1078, which is crap (a falling rod with one end fixed to ground and another end freely falling from 1.8 meter height has its head hit the pavement with as much energy as a dropped apple from 2.7 meter height; but EN 1078 drops severed heads only from 1.5 meter height). In US, the CPSC has 2.0 meter drop height which is far better, but Snell standards have a drop height of 2.2 meters which is the best of the current standards. I'd say buy a Snell certified helmet at least as some of those are available.
• MIPS. It has a valid idea behind it, that the observed helmet non-effectiveness is caused by increased rate of rotational injury. We don't know if the theory is true, but at least it could be true.
• In-mold construction. They have a polycarbonate shell around which the shock absorbing layer is molded. By placing the shell inside the mold, it becomes more rigidly attached to the shock absorbing layer, thus potentially increasing the robustness of the helmet in scenarios above that of the testing (which are not strict enough as a 2.7 meter drop height should be used at least).

Also remember that even if you satisfy this shopping list, helmet effectiveness is still extraordinarily poor. Is it 0% effective against severe injury / death? Or 10% effective? Or 20% effective?

The fact is, we don't know. The only things we know are:

• Cycling is an extraordinarily safe activity. The health benefits of riding a mile far exceeds the health risks of riding a mile, helmet or no helmet.
• A helmet cannot and will not be nowhere as effective as for example a car seatbelt